Triadelphia was laid out and platted in 1838 with 26 lots; at the town center, Juniper and High Streets crossed at right angles; there was also a Center Street.[2] Those streets and names have not survived to the present.
Triadelphia is a name derived from Greek meaning "three brothers" and is thought to have been inspired by Philadelphia, where the Roberts family originated.[3] The three brothers were Joseph, Nathan, and Samuel Roberts. Anticipating the town, Nathan purchased 160 acres from his brother Joseph in 1836, having paid $160.[4]
A post office was established at Triadelphia in 1849, and remained in operation until 1930.[5] The town is thought to have been an important stop on the Underground Railroad due to the activities of William Woodward.[6][7]